Lexus GS300 1998 Owner's Manual page 327

IN CASE OF AN EMERGENCY
B: If no steam is coming from your engine:
Leave the engine running and turn off the air conditioning.
Check the following.
D Is the cooling fan operating?
D Is the coolant in the acceptable range?
D Is the engine drive belt O.K.?
CAUTION
D When the engine is running, keep hands and clothing away
from the moving fan and engine drive belt.
D Do not attempt to remove the radiator cap when the engine
and radiator are hot. Serious injury could result from
scalding hot fluid and steam blown out under pressure.
If the cooling fan is not operating or the coolant is not in the
acceptable range, turn off the engine and call your Lexus
dealer.
If both conditions are O.K., after the engine coolant
temperature has cooled to normal, continue driving your
vehicle.
If the engine coolant temperature does not cool down, or your
vehicle overheats again, have it checked as soon as possible
by your Lexus dealer.
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